The present invention relates to a relatively large numerical aperture and extremely compact zoom lens characterized in a construction of a front lens group thereof, which includes a standard lens view angle in a photographic lens having a covering angle of about 45.degree. and a covering angle of which reaches about 56.degree. at the wide angle end.
A two-lens group type zoom lens of standard size including a standard view angle is well known. In order to miniaturize the lens system it is an important technique to reduce the number of constructive lenses of the overall lens system, particularly in the front lens group having a large effective lens diameter. On the other hand, it is very difficult to reduce the number of constructive lenses in a zoom lens, having a covering angle of about 56.degree. at its wide angle end and a large F-number of about 1:2.8 to 1:3.5 as in the present invention and at the same time achieve satisfactory aberration compensation.
For example, published unexamined Japanese Patent Application No. 51-83543 discloses a relatively large numerical aperture zoom lens system where a front lens group thereof is composed of three lenses which are arranged, in order from the object side, a negative meniscus lens, a double concave negative lens and a positive lens. The number of the lenses in the front lens group of the prior art is the same as that of the present invention. However, in this prior art lens, since a first negative lens is a negative meniscus lens convex toward the object side the distance between the first and second lenses becomes large. This leads to the difficulty of compactness.